[PATCH 5.17 0718/1126] fsi: Aspeed: Fix a potential double free

Greg Kroah-Hartman
2022-04-05T08:36:08Z

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

[ Upstream commit 83ba7e895debc529803a7a258653f2fe9bf3bf40 ]

A struct device can never be devm_alloc()'ed.
Here, it is embedded in "struct fsi_master", and "struct fsi_master" is
embedded in "struct fsi_master_aspeed".

Since "struct device" is embedded, the data structure embedding it must be
released with the release function, as is already done here.

So use kzalloc() instead of devm_kzalloc() when allocating "aspeed" and
update all error handling branches accordingly.

This prevent a potential double free().

This also fix another issue if opb_readl() fails. Instead of a direct
return, it now jumps in the error handling path.

Fixes: 606397d67f41 ("fsi: Add ast2600 master driver")
Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2c123f8b0a40dc1a061fae982169fe030b4f47e6.1641765339.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/fsi/fsi-master-aspeed.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index 8606e55c1721..0bed2fab8055 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -542,25 +542,28 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
return rc;
}

- aspeed = devm_kzalloc(&pdev->dev, sizeof(*aspeed), GFP_KERNEL);
+ aspeed = kzalloc(sizeof(*aspeed), GFP_KERNEL);
if (!aspeed)
return -ENOMEM;

aspeed->dev = &pdev->dev;

aspeed->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(aspeed->base))
- return PTR_ERR(aspeed->base);
+ if (IS_ERR(aspeed->base)) {
+ rc = PTR_ERR(aspeed->base);
+ goto err_free_aspeed;
+ }

aspeed->clk = devm_clk_get(aspeed->dev, NULL);
if (IS_ERR(aspeed->clk)) {
dev_err(aspeed->dev, "couldn't get clock\n");
- return PTR_ERR(aspeed->clk);
+ rc = PTR_ERR(aspeed->clk);
+ goto err_free_aspeed;
}
rc = clk_prepare_enable(aspeed->clk);
if (rc) {
dev_err(aspeed->dev, "couldn't enable clock\n");
- return rc;
+ goto err_free_aspeed;
}

rc = setup_cfam_reset(aspeed);
@@ -595,7 +598,7 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
rc = opb_readl(aspeed, ctrl_base + FSI_MVER, &raw);
if (rc) {
dev_err(&pdev->dev, "failed to read hub version\n");
- return rc;
+ goto err_release;
}

reg = be32_to_cpu(raw);
@@ -634,6 +637,8 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)

err_release:
clk_disable_unprepare(aspeed->clk);
+err_free_aspeed:
+ kfree(aspeed);
return rc;
}

--
2.34.1